Flood hazard assessment on wastewater treatment plants: a case study of the Metropolitan Area of Barcelona (Spain)

This study presents a flood‑hazard assessment of six wastewater treatment plants in the metropolitan area of Barcelona, identifying how streams and ephemeral watercourses—rather than only major rivers—drive inundation risk across the facilities. Using high‑resolution two‑dimensional hydrodynamic modelling, it evaluates why these critical infrastructures are exposed, how different return‑period events affect them, and where high‑hazard zones for workers and equipment emerge. The paper highlights key disaster risk reduction insights, showing that Montcada i Reixac and Vallvidrera face the greatest hazard, while others experience shallow nuisance flooding. 

The paper recommends incorporating small streams into all future hazard assessments, strengthening structural protection such as perimeter walls and elevated platforms, and prioritising adaptation investments at the most exposed facilities. It emphasises that operators should integrate hydrodynamic modelling with exposure data to guide emergency planning, improve worker safety, and support long‑term resilience strategies under changing climate conditions.